The finer structure of the neurones in the nervous system of te white rat

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THE DECENNIAL PUBLICATIONS OF
THE UNIVERSITY OF CHICAGO

THE DECENNIAL PUBLICATIONS

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EDITED BY A COMMITTEE APPOINTED BY THE SENATE

EDWARD CAPPS
STARR WILLARD CUTTING ROLLIN D. SALISBURY

JAMES ROWLAND ANGELL WILLIAM I. THOMAS SHAILER MATHEWS

CARL DARLING RUCK FREDERIC IVES CARPENTER OSKAR BOLZA

JULIUS STIEGLITZ JACQUES LOEB

I

THESE VOLUMES ARE DEDICATED

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THE DECENNIAL PUBLICATIONS
FIRST SERIES VOLUME X

CHICAGO

THE UNIVERSITY OF CHICAGO PRESS

1903

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Copyright 1903

BY THE UNIVERSITY OF CHICAGO

CONTENTS

I. On the Production and Suppression of Muscular Twitchings and

Hypersensitiveness op the Skin by Electrolytes 1

By Jacques Loeb, Professor and Head of the Department of Physi-
ology

II. On a Formula for Determining the Weight of the Central Ner-
vous System of the Frog from the Weight and Length of
its Entire Body - - - - ----- 15

By Henry H. Donaldson, Professor and Head of the Department of
Neurology

III. The Development of the Colors and Color Patterns of Coleop-

tera, with Observations upon the Development of Color in
Other Orders of Insects (with Plates I-III) 31

By William Lawrence Tower, Assistant in Embryology

IV. The Artificial Production of Spores in Monas by a Keduction

of the Temperature 71

By Arthur W. Greeley, Assistant in Physiology

V. The Self-Purification of Streams ------ 79

By Edwin Oakes Jordan, Associate Professor of Bacteriology

VI. The Lecithans: Their Function in the Life of the Cell - 91

By Waldemar Koch, Assistant in Pharmacology

VII. A Contribution to the Physical Analysis of the Phenomena of

Absorption of Liquids by Animal Tissues - 103

By Kalph Waldo Webster, Assistant in Physiological Chemistry

VIII. The Distribution of Blood-Vessels in the Labyrinth of the Ear

of Sus Scrofa Domesticus (with Plates V-XII) - 135

By George E. Shambaugh, Instructor in Anatomy of the Ear, Nose,
and Throat

ix

127055

x Contents

IX. The Animal Ecology of the Cold Spring Sand Spit, with Remarks

on the Theory op Adaptation ______ 155

By Charles Benedict Davenport, Associate Professor of Zoology and
Embryology

X. The Finer Structure of the Neurones in the Nervous System

of the White Rat (with Plates XIII, XIV) - - - - 177
By Shinkishi Hatai, Research Assistant in Neurology

XI. The Phylogeny of Angiosperms - 191

By John Merle Coulter, Professor and Head of the Department of
Botany

XII. Studies in Fat Necrosis - - - - -'- - - 197
By H. Gideon Wells, Instructor in Pathology

XIII. Oogenesis in Saprolegnia (with Plates XV, XVI) - 225

By Bradley Moore Davis, Assistant Professor of Botany [Hdll
Botanical Laboratory]

XIV. The Early Development of Lepidosteus Osseus (with Plates

XVII, XVIII) - 259

By Albert Chauncey Eycleshymer, Assistant Professor of Anatomy

XV. The Structure of the Glands of Brunner (with Plates XIX-

XXIV) - 277

By Robert Russell Bensley, Assistant Professor of Anatomy

XVI. Mitosis in Pellia (with Plates XXV-XXVII) - 327

By Charles Joseph Chamberlain, Instructor in Morphology and
Cytology

XVII. A Description of the Brains and Spinal Cord of Two Brothers
Dead of Hereditary Ataxia. (Cases XVIII and XX of the
Series in the Family Described by Dr. Sanger Brown); (with
plates XXVIII-XXXIX) 347

By Lewellys Franklin Barker, Professor and Head of the Depart-
ment of Anatomy. With an Introduction by Dr. Sanger Brown

THE FINER STRUCTURE OF THE NEURONES IN
THE NERVOUS SYSTEM OF THE WHITE RAT

THE FINER STRUCTURE OF THE NEURONES IN THE
NERVOUS SYSTEM OF THE WHITE RAT

Shinkishi Hatai

The two problems which we have to consider are the fundamental structure of
the ground-substance of the nerve-cells and the manner in which the axone of one
neurone terminates on the dendrites or on the cell-body of another. Many opinions
and theories concerning this structure and these relations have been put forth during
the last decade, and as a consequence the literature of this subject is already very
large. Nevertheless it cannot be said that either of the questions has been definitively
solved. With the aid of a new technique we have been able to see some structures
and relations not heretofore described, and it is the object of the present paper to
interpret and depict these new appearances.

I. TECHNIQUE

For the present investigation a large number of white rats having body-weights
ranging from 5.4 to 185 grams were employed. The material was preserved with
Gilson's fluid, Carnoy's mixture, and the mixtures devised by the present writer
(1901) ; as the staining agents, saturated aqueous solution of thionin followed by a
1 per cent aqueous solution of erythrosin ; Heidenhain's iron-haematoxylin, and
Ehrlich's triacid method were used. In applying these several methods the author's
directions were strictly followed. In each case, after imbedding in paraffin according
to the usual procedure, sections were cut three micra in thickness.

Besides these methods, the present writer tried another method which gave very
satisfactory results in the study of the ground substance of the nerve-cells as well as
in that of the finer structure of their processes. This method is as follows : As soon
as the fresh material was removed from the body, it was put directly into the following
solution. The pieces should not be more than 5 mm.3.

1. Acetic-pic lie-formalin mixture (after the writer, 1901) - - 250 c.c.

2. Acid fuchsin, saturated aqueous solution ----- 50 c.c.

After twenty-four hours the pieces were taken from the solution and were teased
in glycerin with fine needles. In this teased preparation only the achromatic substance
of the nerve-cells and processes stain, while the rest of the cell-substance remains
unstained. For this reason it offers us several advantages for the study of the minute
structure of the axone and dendrites not possessed by other methods which were
employed. Although this preparation gives such satisfactory results, it cannot be
preserved permanently, as the color soon fades. To meet this difficulty, the material
thus preserved and stained may be imbedded in paraffin after having been carried

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Structure of Neurones in Nervous System of White Rat

through 95 per cent, and 100 per cent, alcohol and xylol. In this case, however, the
section must be restained upon the slide. These restained preparations give clearer
pictures than those obtained by other methods, and, in addition, show a distinction
between the axone and the dendrites. The appearances about to be described were
obtained by this method.

II. THE FINER STRUCTURE OP THE GROUND SUBSTANCE OF THE NERVE-CELLS,
ESPECIALLY OF THE SPINAL GANGLION CELLS

The spinal ganglion cells in the white rat present at least two varieties differently
characterized ; one of the varieties is larger in size and stains faintly with eosin or
erythrosin ; while the other shows just the opposite characters, that is, the cell-bodies
are smaller and stain deeply with these solutions. The present description of the
spinal ganglion cells is based on the study of the larger variety which has been
regarded by the writer as the fully matured form (1901).

In general, the cell-body shows a circular or a somewhat oblong shape, containing
a single nucleus which lies at or near the center of the cell. The nucleus contains a large
number of the oxyphile particles of various sizes. These particles are most abundant
at the periphery of the nucleus as well as around the nucleolus which lies near its
center. These particles hang along the fine filaments of the linin substance which
forms a very complicated network in the nucleus (Plate XIII, Fig. 1). By using
toluidin blue and eosin, the oxyphile substance and the linin stain red, while the
nucleolus stains an intense blue, owing to the accumulation of the basophile substance
around the oxyphile substance which forms the nucleolus proper (1901 3).

The distinction between the oxyphile and the linin substance may be made out by
the fact that the latter stains more faintly. The nuclear membrane is distinctly
visible, showing a somewhat reddish brown color. The cell-body proper is composed
of at least two different substances, as is the case in all other nerve cell-bodies, namely
(1) the stainable substance known also as tigroid, Nissl's bodies, chromatophile
particles, etc., and (2) non-stainable or ground substance. The stainable substance
just mentioned appears to fill up the cell- body, except in two regions, one along the
periphery of the cell-body and the other around the nucleus, the regions being
known respectively as the peripheral and the inner, clear zones (Lenhossek, 1895). In
these two regions the non-stainable substance alone is visible.

Under a low magnification the cell-body appears as a red homogeneous mass
with a bluish tinge in it. A higher magnification of such a cell reveals a large number
of minute meshes presenting a reticular arrangement. These meshes, however, are
not similar either in shape or in size, but differ very widely according to regions in
which they occur. They are formed by very delicate protoplasmic filaments within
which minute granules are clearly distinguishable. These granules are known as
"neurosomes." The nourosome seems to be a very highly differentiated cvtomicrosome
and to form the main part of the filament. The neurosome stains much deeper
with eosin or erythrosin than ordinary cyto-microsome, and also is much larger than it.

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Shinkishi Hatai

As was pointed out by Held (1897), the neurosome is not only found imbedded within
the filament, but appears also in the meshes between the filaments. The neurosomes
in the region of the terminal end of the axis cylinder are very much larger than those
found in the rest of the neurone (Plate XIII, Fig. 1).

As has already been mentioned, the meshes formed by the filaments are highly
variable both in size and in shape. Generally, in the clear zone at the periphery of
the cell-body, the meshes are larger and more conspicuous than in the remaining part.
In the neighborhood of the axone hillock the meshes are not only much diminished in
siae, but they are also elongated. Around the nucleus these meshes reach a minimum
size. The form of the reticulum at the periphery shows meshes of a somewhat poly-
gonal shape, but in the remaining part of the cell these meshes are elongated, especially
around the nucleus and near the axone hillock. These modified meshes present a
fibrillar appearance, especially those around the nucleus as well as in the neighbor-
hood of the axone hillock, owing to the alteration which has been described ; that is,
the elongation of the meshes diminishes the original space contained between the
filaments and renders the filaments approximately parallel. In some cases several of
these filaments unite together and form very thick strands. These secondary altera-
tions take place throughout the cell-body and around the nucleus, but never occur at
the periphery of the cell. Thus, the fibrillar structures as well as the fibrillar network
within the cell-body are produced. These fibrils, therefore, are very different from those
described by Apathy and Bethe. According to Golgi (1898) and others, a modified
silver-nitrate technique brings out a new structure within the nerve-cells. This
structure presents very complicated network around the nucleus, and to this the name
" endocellular network" has been given. It seems probable that the endocellular net-
work just mentioned may be one expression of the elongated meshes of the fibrillar
substance observed by the writer. Since Golgi's technique does not bring out the
very minute structures, the figures obtained by him are only a fragment of the network
which we have described. I will take up this point later on and will present the evi-
dence I have for identifying this endocellular network with the structure to be seen
within rats' nerve-cells.

Among the neurologists, two different views concerning the structure of the
ground substance in the nerve-cells are held : These may be designated as? ( 1 ) the
fibrillar, and (2) the non-fibrillar or reticular. These two appearances in the proto-
plasm have been brought out by using different techniques. Apathy (1895) demon-
strated the fibrillar structure in the annelid nerve-cells by using gold chloride ; Bethe

(1897) in the Crustacea, killed with nitric acid and stained with toluidin blue; Cox

(1898) by osmic acid ; Flemming (1895) by his own fixing agent; Dogiel by methylen
blue; Becker (1895) by Weigerts' copper and hematoxylin stain; Kronthal (1895) by
staining freshly crushed and dried specimens with methylen blue, etc., while the reticular
stiucture was obtained by Butchli, Held, Lenhossek, Van Gehuchten, Cajal, and others,
using either strong alcohol, corrosive sublimate, Gilson's mixture, or Carnoy's solution.

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6 Structure of Neurones in Nervous System of White Rat

The writer has had the opportunity to study the preparations made after the
method of Bethe, Dogiel, and Kronthal, and to compare those with his own preparations
from the white rat. In these cases, however, the writer was unable to see any fibrillar
structure, such as had been described by those writers, but observed only a reticulum
producing pseudo- fibrils. Although the reticular structure of the ground substance
seems to be characteristic for young and unmodified nerve-cells, nevertheless in the
large multipolar cells it has been altered to such an extent as to present a fibrillar
appearance such as is seen in axone hillock of the spinal ganglion cells and around the
nucleus. This alteration is probably due to growth changes, as was pointed out by the
writer (19014) in an earlier paper.

So far as my observations go, the fibrillar structure of the ground substance in
the nerve-cells of the white rat is merely a modified network, and consequently it can-
not be compared with the fibrillar structures described by Bethe and Ap&thy.

III. FINER STRUCTURE OF THE AXONES AND DENDRITES

Both the axones and dendrites are direct prolongations of the cell-body and pre-
sent wide variations in their shape, size, and length, according to the cell-bodies from
which they arise.

1. Structure of the axones. — An axone originates, as a rule, from a specially dif-
ferentiated portion of the cell-body known as the "axone hillock." The axone hillock
appears under the microscope as a cone, being clearly marked off from the surround-
ing cytoplasm by the absence from it of the Nissl granules. Under a higher magnifi-
cation this area of the axone hillock is seen to be composed entirely of delicate filaments
formed by rows of neurosomes and stains more intensely than the rest of the cell (Plate
XIII, Fig. 1). These delicate filaments run convergently from the cell-body to the
axone and produce well-known radial arrangement of the filaments. These filaments,
however, are not real fibrils, but, as has already been mentioned, they are modifications
of the reticulum, and the so-called fibrils in this region are connected with one another
by the delicate side branches. In other words, the axone, like the cell-body, is composed
of a reticular arrangement of the cytoplasm and may be regarded as an extension of the
cell-body proper. The ground substance, or the reticulum, of the cell-body, as well as the
axone, ifi composed of cyto-microsomes and neurosomes. The neurosomes in the axone
seem to be more differentiated than those in the cell-body proper, for they show a
stronger affinity for acid dyes, especially in the terminals of the axones. It is inter-
esting to note that the pseudo-fibrils in axones are packed very densely, and therefore
the real structure of the primitive reticulum is hard to make out. The structure of the
axone may be well studied by examining the cross-sections of the terminals (Plate XIII,
Figs. 2, 3, 4 ; Plate XIV, Figs. 5, 6.) The neurosomes which form the terminals of the
axis cylinder are very conspicuous, both by their size and by the manner in which
they stain. The size of the individual neurosome in such terminals is a trifle larger
than in the axone proper and stains a more intense red. It is already known that the

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Shinkishi Hatai

axis cylinder at its end enlarges greatly and forms the so-called " axis cylinder plate."
An enlargement of the axone terminal may be seen in Figs. 5 and 6. Especially in
Fig. 5, where the nerve-fibers enter into the granular layer of the cerebellar cortex,
there is to be seen an enormous enlargement of the axones to several times their
original diameters. A detailed description of the structure of the axone terminals and
their relation to the surrounding neurones willbe given later.

2. Structure of the dendrites. — The internal structure of the dendrites shows a
close resemblance to that of the cell-body. Besides the ground substance which stains
faint red, as in the case of the cell-body proper, it contains Nissl granules. Unlike
the axone the dendrite contains but a small amount of the ground substance, and, fur-
ther, the size of the individual neurosomes is approximately the same as that of the
cyto-microsomes, where they stain more faintly than the neurosomes in the axone. In
other words, the neurosomes in the dendrites do not show much differentiation from
the cyto-microsomes. The reticulum, however, presents a marked alteration, exhibiting
in some cases (Plate XIII, Fig. 4) a fibrillar arrangement. A most interesting feature
of the dendrite is the nodules or gemmules which develop along its periphery. By
the Golgi technique they stand out like pin-head prolongations or knobs. The
presence of these gemmules on the dendrites has been denied by Hill (1896), while
the other investigators regard them as very important and constant structures in
certain forms of nerve-cells (Van Gehuchten, 1897, Cajal, and others). Still another
interpretation has been made by Demoor (1896, 1898), who considers the moniliform
appearance of the dendrite as a condition in which the gemmules are partially retracted
and regards them as important for the normal activity of nerve-cells. I agree
with the view which regards these structures as a constant character of certain forms
of the nerve-cells. This knob-like structure can be seen not only in specimens pre-
pared by the Golgi technique, but also in those prepared by my own method. In this
case we can see clearly the internal structure of the gemmules and their relations to the
main body of the dendrite. The gemmules are nothing more than a local extension of
the ground substance of the dendrites, and a more or less modified reticulum can be
seen within them in many cases (Plate XIII, Fig. 4). It is difficult, however, in some
instances to distinguish the gemmules from the surrounding structures, when a large
number of the neurosomic chains forming the axone terminals surround the dendrite
very densely. Careful observation shows that the neurosomes in the gemmules stain
less deeply than those forming the terminals. The accumulation of neurosomes to
form gemmules is shown in Fig. 4, which has been drawn from the cells in the cerebral
cortex of the adult white rat.

IV. TERMINATION OF THE AXONE ON THE DENDRITES AND CELL-BODIES

1. Termination of the axone on the cell-body. — The actual termination of the
axone on the cell-body as well as a diffused network of the nerve-fiber terminals
surrounding the cell-body and forming the so-called "pericellular network" has been

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8 Structure of Neurones in Nervous System of White Rat

observed by Semi Meyer (1896), Held (1897), Ramon y Cajal (1899), Golgi and his
students, and others.

In certain kinds of neurones the present writer has also been able very clearly
to see these phenomena in his preparations. The cerebellar cortex is a most favorable
locality in which to see the termination of the axones on the cell-body. It is a well-
known fact that the Purkinji cells are surrounded by the terminals of the collaterals of
the so-called basket cells, located in the molecular layer. Fig. 5 (Plate XIV) illustrates
these terminations. In this figure the Purkinji cells are represented in sepia and the
axone endings by a deep red. As can be seen, a large number of the neurosomes
appear surrounding the basal portion of the cell-bodies together with their axones, and
form a basket ; while the upper part of the cell-body is in contact with a small number of
the neurosomes along the cell-wall. According to the existing view, the basket-forming
fibers are derived only from the collaterals of the axones of the cells which lie in the
molecular layer. Contrary to this view, the writer believes that the fibers which form
the basket have at least two sources of origin: that is, one from the molecular cells and
the other from the so-called moss-fibers. This conclusion was drawn from the following
evidence : by examining Fig. 5 (Plate XIV) one can easily see that the main part of the
fibers which form the basket including the basal portion of the Purkinji cells descend
toward the medullary layer and become continuous with some of the fibers in that layer.
In other words, some of the fibers which enter into the granular layer enlarge very much
and ascend as far up as the Purkinji cell layer, where they surround the latter very
intimately and form the so-called "basket" in company with the descending collaterals
from the cells in the molecular layer. In the same figure the sections of the main
trunks, as well as the lateral branches of the moss-fibers in various planes, are shown
distributed throughout the granular layer. In many cases these cross-sections of the
moss-fibers are surrounded by the neurosomes which stain lightly. These structures,
formed by the two kinds of the neurosomes, correspond probably to the glomeruli ; and
the neurosomes which stain lightly are identical with those which form the dendritic
branches of the granular cells, while the rest of the neurosomes are those which form
the moss-fiber.

An appearance similar to the basket of the Purkinji cells has been observed by
the writer in the case of the cells in the Amnion's horn. Fig. 4 (Plate XIII), which
has been drawn from the cells in the Amnion's horn, in the adult white rat shows the
basal portion of the cell-body densely surrounded by the axones of another neurone
forming a pericellular network.

The termination of the nerve-fibers on the cell-body in the corpus trapezoideum
has been described by several investigators, especially by Held (1895). In the case of
these neurones, according to him, the terminals of an axone come into contact relation
with the cell-body of another neurone, yet one can always make out where the proto-
plasm of one neurone ends and where that of the second begins. Further, the line of
demarkation is more refractive than the adjacent protoplasm. He finds, however, that

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Shinkishi Hatai 9

this refractive limiting line is not demonstrable in the adult and comes to the con-
clusion that during the processes of growth the protoplasm of the related neurones
fuses.

As is stated by Held, the cells in this locality are very favorable for the study of
the termination of the axones. As Fig. 6 (Plate XIV) shows, the terminals of an axone
come in contact with the cell-body along a groove or an elongated depression. This
groove on the cell-surface may coincide with the refractive area of Held. In most cases
more than one axone terminates on a single cell-body. Fig. 6 was drawn from the
material taken from a young white rat having a body- weight of 4.5 grams. In this
stage a number of axones terminate on each cell-body. No special area for the termi-
nation of the axones appears, since they are found in all regions of the cell-body, some-
times at the center and sometimes at the end of it. In all cases the terminals of the
branches present mere contiguity to the cell-surface, and neither fusion of one with the
other nor a pericellular network of the axones is found. It is to be noted that these
observations apply to the white rat, while the observations of Held were made on the
rabbit. Whether the cell-body in the rat becomes fused with the axones in adult life
has still to be determined.

A relation between axone and cell-body similar to that in the corpus trapezoideum
can be observed in the ventral horn cells of the spinal cord. Fig. 2 (Plate XIII),
which was drawn from the preparation of an adult white rat, illustrates this. In this
figure the cell-body is represented by sepia while the axone endings are colored an
intense red.

2. Termination of the axone on the dendrites. — As has already been mentioned,
the gemmules are lateral extensions of the dendrites, and their essential structure is
the same as that of the dendrites. A careful observation of the preparation shows that
the axones in most cases surround the dendritic branches and approach so closely to the
gemmules that these two structures often come into contact. As Fig. 4 (Plate XIII)
shows, the cell-bodies in the Amnion's horn are densely surrounded by the axones and
some of the latter climb along the surface of the dendrites and there come into contact
with the gemmules. This relation is even more clearly shown in the cerebellar cortex.
It is already known that the dendrites of the Purkinji cells are densely surrounded
by several kinds of the axones ; namely, those of the granular cells, those form-
ing the climbing fibers, and those which form the moss-fibers. The axone termi-
nals which surround the dendrites come, in most cases, actually in contact with
the latter. Fig. 5 (Plate XIV) shows such a relation between the two processes
where the dendrites are represented in sepia, while the axones are colored an
intense red.

The so-called "glomeruli " formed by the axones and dendrites form the most favor-
able structure for the study of an intimate relation between the two processes. This
structure is found best developed in the olfactory-bulb and less developed in the granu-
lar layer of the cerebellar cortex. The olfactory glomeruli in Fig. 3 (Plate XIII) were

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10 Structure of Neurones in Nervous System op White Rat

drawn from that of the new-born white rat having a body-weight of 4.5 grams. For con-
venience the axones are represented in red, while the dendrites are in yellow. Although
the olfactory glomeruli are of very complicated structure, owing to an intricate arrange-
ment of the two kinds of the processes, yet, after knowing the character of the axone
and dendrite as determined by the neurosomes in them, one can easily see that in
many cases a single long and apparently continuous filament is composed of two dif-
ferently characterized parts ; that is, the neurosomes in one portion are much larger
and stain more deeply than those found in the other portion. In other words, these
apparently continuous lines are composed of two different structures, the axones and
the dendrites. In the case of the glomeruli in the granular layer of the cerebellar
cortex, continuous filaments formed from two sorts of processes, as observed in the
olfactory glomeruli, were not found, but a mere contiguity of the two processes, such
as is noticed in the dendrites of the Purkinji cells and the axones which surround them,
was all that could be observed.

GENERAL REMARKS

The history of the investigations on the neurone has been beautifully summar-
ized by Goldscheider and Flatau (1898), Barbacci (1899), Barker (1899), Robertson
(1899), Soury (1899), and Van Gehuchten (1900), but in order to show the bear-
ing of our own observations, it will be necessary briefly to review the more important
theories concerning the neurone.

According to the most prevalent view, the "neurone" or the nerve-cell with all
its processes may be regarded as an independent element, from the anatomical stand-
point ; consequently the entire nervous system is an aggregation of those independent
elements. This view was first brought out by Waldeyer (1891). He says:

Das Nervensystem besteht aus zahlreichen untereinander anatomisch wie genetisch nicht
zusammenhangenden Nerveneinheiten (Neuronen). Jede Nerveneinheit setzt sich zusammen
aus drei Stiicken: der Nervenzelle, der Nervenfaser und dem Faserbaumchen (Endbaumchen).
Der physiologische Leitungsvorgang kann sovvohl in der Richtung von der Zelle zum Faser-
baumchen als auch umgekehrt verlaufen. Die motorischen Leitungen verlaufen nur in der Rich-
tung von der Zelle zum Faserbaumchen, die sensiblen bald in der einen, bald in der anderen
Richtung.

This view of Waldeyer, or the neurone doctrine, has been somewhat modified since
Held, in 1896, noticed in some neurones an actual contiguity of the axones both with
the cell-bodies and dendrites. Held's observation was very soon confirmed by a num-
ber of investigators and was further extended to another group of neurones. Held's
observation, however, does not oppose the neurone doctrine, for he notices a mere con-
tiguity of the axones with the cell-body and dendrites and not an organic continua-
tion of one into the other. In the following year Bethe (1897) published an article
in which he claims that the nerve-cells and dendrites contain a great number of primi-
tive neuro-fibrils which run toward the axone and form the nerve-fiber. That is, the
nerve-fiber is composed of these primitive fibrils. He believes, further, that the fibrils

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Shinkishi Hatai 11

of one neurone enter into the nerve processes of other neurones, and thus two neurones
become continuous by means of these primitive fibrils. The observations were made
on Crustacea. Apathy's (1897) observation on the lower animals (annelids) contradicts
radically the neurone doctrine, for he was able to follow the primitive neuro-fibrils
which come from one ganglion cell and enter into the cell-body of another element,
where they become fused with the protoplasm. Anastomosis of the axones with den-
drites has been observed by several other investigators, for instance, Ballowitz (1893),
Heymansand Demoor (1894), and others; but in these cases always in the peripheral
system. Thus Gerlach and Golgi's hypothesis of a diffuse network of the nerve-
processes has been revived through a more careful investigation of modern
neurologists.

It is impossible at the present moment to say which of these views is correct, since
we do not know absolutely which technique shows the tissue in most nearly normal
condition. But after examining the results obtained by several investigators, it seems
to be quite reasonable to say that Golgi's silver-nitrate technique is not effective
enough to bring out the minute structures of the neurones, and, further, it acts on the
tissue so irregularly that in some cases even the same tissue in the same condition
presents a widely different appearance. In addition, the ordinary silver-bichromate
method does not show the internal structure of the neurones. Consequently, for the
purpose of this discussion, results obtained by Golgi's technique can hardly be con-
sidered as at all conclusive.

As has already been mentioned, the nerve-cells in the white rat present a fibrillar
structure owing to the parallel arrangement of the neurosomes. This structure, how-
ever, is merely a modified reticulum which has been very much elongated. In some
cases several of these parallel lines of the elongated meshes combine together and form
very thick strands. Further, these united filaments or strands are found throughout
the cell-body, forming a very complicated network. In the case of the dendrites these
united filaments are noticed most frequently. Now, comparing these figures with that
of Golgi's endocellular network previously mentioned, one might expect the two figures
to be identical, for this anastomosis of combined filaments in the cells in the white
rat occurs only around the nucleus and in the neighborhood of the axone hillock,
not in the hillock itself, and never occurs along the periphery of the cell-body, where
wide meshes of a polygonal shape are alone visible. Golgi's endocellular network has
a similar distribution within the cell-body. A similar arrangement has been observed
in the cells of cerebral and cerebellar cortex. The only difference between Golgi's
results and those of the present writer is that Golgi's network is much simpler than
the latter and does not show any minute meshes formed by delicate filaments. This
difference is due very probably to an insensitiveness of Golgi's technique, so that it
does not bring out these minute structures.

It has been suggested by some investigators that Golgi's endocellular network
might represent the system of the intracellular canaliculi of Holmgren. If Golgi's

187

12 Structure of Neurones in Nervous System of White Rat

endocellular network is really homologous to the canal system described by Holmgren,
it should occur along the cell-periphery where this canal system is most abundant as
well as larger in diameter. Further, as has been pointed out by Soukanoff (1902),
these two structures do not show any similarity in appearance.

The present writer thinks also that the anastomosis of fibrils of Ap&thy within the
cell-body may be a homologous structure to both Golgi's endocellular network as well
as to the network here described. Judging from its manner of distribution and posi-
tion in the cell-body, they are nearly identical with one another. Slight variation
in the structure depends upon the tissues taken from animals which are widely
different. The more complex anastomosis of Apathy are due to the greater accuracy
of technique.

It seems to me, therefore, that the fundamental structure of the ground substance
in the nerve-cell shows reticular arrangement, which, however, becomes sooner or later
elongated, and thus the fibrillar appearance in the axone hillock, axone, and dendrite,
and the complicated anastomosis in the cell-body, are brought out in the way previously
described.

As will be seen from the previous description, certain nerve cell-bodies, such as
Purkinji's, the pyramidal cells and the cells in the corpus trapezoideum and ventral horn
of the spinal cord, are densely surrounded by the terminals of the axones, and in some
cases not only surrounded, but some of the axones terminate on the cell -body and
become contiguous with it. Further, the dendritic processes, especially the gemmules,
are as a rule very densely surrounded by the axone terminals. In all these cases,
however, those two kinds of structures are merely in contact with each other, and the
present writer was not able to see any actual continuity between the two. Even in the
case of the olfactory glomeruli, where the axones and dendrites unite and form a single
filament, these two structures can nevertheless be clearly distinguished. I conclude,
therefore, that, although the two structures appear continuous with one another, never-
theless the junction point can always be recognized by the differences in structures in
either side of it.

BIBLIOGRAPHY

Apathy. " Das leitende Element des Nervensystems und seine topographischen Beziehungen

zu den Zellen." Mittheil. d. Zool. Stat, zu Neapel, XII, 1897.
Ballowitz. " Ueber das Vorkommen echter peripherer Nervenendnetz." Anat. Anz., IX, 1893.

" Die Nervenendigungen der Pigmentzellen." Zeitschr. f. wiss. Zool., LVI, 1893.
Barbacci, O. " Die Nervenzelle in ihren anatomischen, physiologischen und pathologischen

Beziehungen nach den neuesten Untersuchungen." Centralbl. f. allg. Pathol, u. pathol.

Anat., X, 1899.
Barker, L. The Nervous System and its Constituent Neurones. New York, 1899.
Becker. " Haematoxylin-Kupfer Farbung der Nervenzellen." Arch. f. Psychiatrie, XXVII,

1895.

188

Shinkishi Hatai 13

Bethe. "Ueber die Primitivfibrillen in den Ganglienzellen von Menschen und anderen

Wirbeltieren." Morpholog. Arbeiten, VIII, 1898.
" Das Nervensystem von Carcinus maenas." Arch. f. mikrosk. Anat., L, 1897.
Cajal, Ramon y. Textura del sistema nervioso del hombre y de los vertebrados. Madrid,

1899.
Cox, W. H. " Der feinere Bau der Spinalganglienzelle des Kaninchens." Anatomische

Hefte, X, Heft 1, 1898.
Demoor, J. " Plasticity morphologique des neurones cer6braux." Arch, de biologie, XIV,

1896.
"La mechanisme et la signification de l'6tat moniliforme des neurones." Travailles de

laboratoire de Vinstitut Solvay, 1898.
Flemming. " Ueber den Bau der Spinalganglienzellen bei Saugethiere." Arch. f. mikrosk.

Anat., XLVI, 1895.
Gehuchten, Van. Anatomie du systeme nerveux de Vhomme. Louvain, 1900.
Goldscheider und Flatau. Normale und pathologische Anatomie der Nervenzellen auf

Grund der neueren Forschungen. Berlin, 1898.
Golgi, C. " Sur la structure des cellules nerveuses." Arch. ital. de biol., Turin, XXX, 1898.
Hatai, S. " The Finer Structure of the Spinal Ganglion Cells in the White Rat." Jour. Comp.

Neurol., XI, No. 1, 1901.
"On the Presence of the Centrosome in Certain Nerve Cells of the White Rat." Ibid.
" On the Mitosis in the Nerve Cells of the Cerebellar Cortex of Foetal Cats." Ibid., No. 4.
"Observations on the Efferent Neurones in the Electric Lobes of Torpedo Occidentalis."

Jour. Cincinnati Soc. Nat. Hist., XX, No. 1, 1901.
Held. " Beitrage zur Structur der Nervenzellen und ihrer Fortsatze." I. Abhandl., Arch. f.

Anat. u. physiol., Anat. Abth., 1895; II. Abhandl., ibid., 1897; III. Abhandl., ibid.,

Supplbd., 1897.
Heymans et Demoor. "Etude de l'innervation du coeur des vert6bres a l'aide de la m^thode de

Golgi." M6moires couronne's et autres me'moires de Vacad. royale de me~d. de Belgique,

1894.
Jaworowski, Miecislan. " ' Apparato reticolare ' von Golgi in Spinalganglienzellen der

niederen Wirbelthiere." Bull, intern, acad. sci., Cracovia, 1902.
Kopsch, F. " Die Darstellungen des Binnennetzes in Spinalganglienzellen und anderen Korper-

zellen mittels Osmium-Satire." Sitzungsber. d. k. Akad. d. Wiss. zu Berlin, 1902.
Lavdowsky. " Von Aufbau des Ruckenmarks." Arch. f. mikrosk. Anat., XXXI, 1891.
Lenhossek, v. " Ueber den Bau der Spinalganglienzellen des Menschen." Arch. f. Psychiat.

u. Nervenkr., XXIX, 1895.
Meyer, S. "Ueber eine Verbindungsweise der Neuronen; nebst Mittheilungen iiber die

Technik und die Erfolge der Methode der subcutanen Methylenblauinjection." Arch. f.

mikrosk. Anat, XLVII, 1896.
Robertson, W. F. "Normal and Pathological Histology of the Nerve Cell." Brain, XXII,

1899.
Soukhanoff. " Sur le reseau endocellulaire de Golgi dans les elements nerveaux de l'ecorce

cerebrale." La Neurax, IV, F. I., 1902.
Soury, J. Le systeme nerveux central. Paris, 1899.
Waldeyer. " Ueber einige neuere Forschungen im Gebiete der Anatomie des Centralnerven-

systems." Deutsch. medic. Wochenschr., No. 44, 1891.

189

14 Structure of Neurones in Nervous System of White Eat

EXPLANATION OF THE PLATES

PLATE XIII

Fig. 1.— Spinal ganglion cell from a cervical ganglion of the adult white rat. Reddish-
brown (surrounding the cell -body) represents the capsule which is composed of connective
tissue. Several sheath-nuclei as well as a cross-section of a capillary containing the blood cor-
puscles are shown. Within the cell the larger red granules represent the neurosomes, while the
smaller granules of the same color represent the cyto-microsomes. The nucleus which is rep-
resented also in red contains a single nucleolus (blue) and a large number of the oxyphile gran-
ules (red). Nissl bodies are represented in blue. The location of the axone hillock is indicated
by the absence of the Nissl bodies.

Fig. 2. — A motor cell from the ventral horn of the spinal cord of the adult white rat.
Lighter red represents the body of the motor cell which contains a spherical nucleus (slightly
darker red) at the center. The dots of an intense red represent the neurosomes which form the
axone endings. They terminate on the surface of the cell-body.

Fig. 3. — An olfactory glomerulus of the new-born white rat, having body-weight of 4.5
grams. Red lines represent the olfactory nerve-fibers, while the yellow lines represent the den-
dritic branches of the mitral cells- The neuroglia nuclei are represented in blue.

Fig. 4. — Cells from Cornu ammonis of the adult white rat. The larger cell (on the left
side) shows a mode of termination of axones which are composed of a large number of the neu-
rosomes. The small cell represents the internal structure of the cell-body. The neurosomes are
represented by red dots, while the nucleus in which is a single nucleolus (blue) and a large
number of the oxyphile granules (red) is outlined in red. Blue in the cytoplasm represents the
Nissl bodies.

PLATE XIV

Fig. 5. — The cerebellar cortex of the adult white rat. Purkinji cells and their dendrites
are represented in sepia. Nerve-fibers and neurosomes are represented in red. Nuclei in both
granular and molecular layers as well as the blood capillaries are represented with black.

Fig. 6. — Cells from corpus trapezoideum of the young white rat having body- weight of 4.5
grams. Each nucleus contains a single nucleolus (blue) and a large number of the oxyphile
granules (red). Blue in the cytoplasm represents the Nissl bodies. Red lines (heavier) represent
the terminals of the axones while the lighter lines in the outside of the cell-bodies represent
either the neuroglia fibers or fine nerve-fiber?.

All the figures were drawn from restained preparations (see the technique in the text)
by free hand, using Obj. h X OC, 4, Zeiss, except Fig. 5, which has been drawn by using
Obj. 4, 0 mm. X OC. 4, Zeiss.

190

Decennial Publications, X

Plate XIII

* Ik 8&

Fig. 1

Fig. 2

\

Fig. 3 Fig. 4

Fig. 1. Spinal Ganglion Cell from White Rat

Fig. 2. Ventral Horn Cell from White Rat. Axone Terminations

Fig. 3. Olfactory Glomerulus. Newborn White Rat

Fig. 4. Cells from Cornu Ammonis of White Rat. Gemmules

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